Bump com.puppycrawl.tools:checkstyle from 13.5.0 to 13.6.0 on Java 21

and up.

Author: garydgregory

pom.xml

@@ -1778,7 +1778,7 @@
         <jdk>[21,)</jdk>
 	  </activation>
       <properties>
-        <commons.checkstyle.version>13.5.0</commons.checkstyle.version>
+        <commons.checkstyle.version>13.6.0</commons.checkstyle.version>
         <argLine>-XX:+EnableDynamicAgentLoading</argLine>
       </properties>
     </profile>

src/changes/changes.xml

@@ -61,7 +61,8 @@ The <action> type attribute can be add,update,fix,remove.
         <!-- FIX -->
         <!-- ADD -->
         <!-- UPDATE -->
-        <action type="update" dev="ggregory" due-to="Gary Gregory">Bump org.cyclonedx:cyclonedx-maven-plugin from 2.9.1 to 2.9.2.</action>        
+        <action type="update" dev="ggregory" due-to="Gary Gregory">Bump org.cyclonedx:cyclonedx-maven-plugin from 2.9.1 to 2.9.2.</action>
+        <action type="update" dev="ggregory" due-to="Gary Gregory">Bump com.puppycrawl.tools:checkstyle from 13.5.0 to 13.6.0 on Java 21 and up.</action>
       </release>
       <release version="102" date="2026-06-07" description="This is a feature and maintenance release. Java 8 or later is required.">
         <!-- FIX -->